function errorImg(img,type) {
	var _url = '#';
	if(type=='user'){
		_url = '/img/xy.jpg';
	}else if(type='course'){
		_url = '/img/course/course.jpg';
	}else if(type='articles'){
		_url = '/img/logo0.jpg';
	}
	img.src = _url;
	img.onerror = null;
}